三种头孢类药物与牛转铁蛋白间相互作用的光谱特征

发布时间：2018-10-20 14:24

【摘要】：目前,由于受环境等多方面的影响,人们对药物的需求也越来越多。对药物的研究也越来越多的受到人们的关注。药物在人体发挥作用离不开相应蛋白质的配合,因此研究蛋白质与药物的结合机理至关重要。本文就牛转铁蛋白与头孢类药物的相互作用结合了多种方法进行了研究。实验探究包含下列各部分:第一章:参考34篇文献就蛋白质大分子-药物小分子结合机制的不同研究方法进行了综述,介绍了多种光谱法,包括荧光猝灭法、紫外吸收光谱法、圆二色光谱法等。简单总结了蛋白质对于生物体的多种功能。第二章:将牛转铁蛋白(TRF)作为研究对象,298 K、310 K和318 K三个温度下对牛转铁蛋白与头孢呋辛钠(CSI)的相互作用进行了实验。由实验数据知:TRF、CSI的作用位点近似为1,提高温度Ka变小,表示TRF、CSI反应生成的产物的稳定性降低,该荧光猝灭过程是静态的。ΔS0、ΔG0,表示该过程属于自由能降低且熵增的自发过程。第三章:将转铁蛋白的荧光变化作为研究对象,在298 K、310 K、318 K下采用紫外吸收、传统荧光、同步荧光、圆二色谱法,对TRF与头孢噻肟钠(CEM)的结合综合分析。数据处理和分析显示:TRF的荧光伴随CEM浓度的提高而呈现规律性猝灭,猝灭方式是静态的,两者借助静电作用结合,反应生成新物质。结果的准确性通过上述方法进行了验证。此外,同步荧光和圆二色谱也表明CEM影响了TRF的构象。第四章:分别以TRF、牛血清白蛋白(BSA)为研究对象,就TRF、BSA与CSI之间的结合机理运用多种方法实施了研究。结果表明:伴随CSI的加入,BSA、TRF的吸光度峰值减小,最高吸光度所对应的峰位置有3 nm、5 nm的红移,表示CSI与BSA、TRF间有新物质生成,CSI对BSA、TRF吸收光谱的猝灭是静态的。TRF、BSA与CSI的结合作用影响了TRF的α-螺旋结构,导致其变得松散且使得TRF的荧光猝灭。尽管CD峰的峰值有所变化,但其峰形与位置都没受到影响,从而证明在TRF、BSA中主要结构依然是α-螺旋。第五章:以TRF为研究对象,对TRF-头孢西丁钠(CFS)体系的作用机理进行了研究。结果显示:提高温度Ka变小,表示TRF、CFS反应生成的产物的稳定性降低,该荧光猝灭过程是静态的,ΔH0,ΔS0,表示TRF、CFS凭借静电作用力而结合。λex=280 nm时对应的猝灭水平大于λex=295 nm时的荧光猝灭水平,进而可知CFS与BSA、TRF相互结合过程中同时有Trp、Tyr两者的参与。多种方法应用于同一研究可以使所得结果更精确,因此在此研究的基础上仍可拓展和探索新的方法。
[Abstract]:At present, due to the environment and other aspects of the impact, the demand for drugs is also increasing. More and more people pay attention to the study of drugs. It is very important to study the mechanism of protein-drug binding because the function of drugs in human body is inseparable from the cooperation of corresponding proteins. The interaction of bovine transferrin with cephalosporins was studied in this paper. The experimental study consists of the following parts: chapter 1: the different research methods of protein macromolecular-drug small molecule binding mechanism are reviewed with 34 references, and a variety of spectroscopic methods, including fluorescence quenching method, ultraviolet absorption spectrometry method, are introduced. Circular dichroism, etc. This paper briefly summarizes the various functions of proteins for organisms. Chapter 2: the interaction between bovine transferrin and cefuroxime sodium (CSI) was studied at 298K 310K and 318K using bovine transferrin (TRF) as the research object. The experimental data show that the interaction site of TRF,CSI is approximately 1, and the increasing temperature of Ka becomes smaller, which means that the stability of the product produced by TRF,CSI reaction is decreased, and the fluorescence quenching process is static. 螖 S _ 0, 螖 G _ 0, which means that the process belongs to the spontaneous process of decreasing free energy and increasing entropy. In chapter 3, the fluorescence changes of transferrin were studied. UV absorption, traditional fluorescence, synchronous fluorescence and circular dichroism were used to analyze the binding of TRF with cefotaxime sodium (CEM) at 298K ~ 310K ~ 318K. Data processing and analysis show that the fluorescence of TRF is quenched regularly with the increase of CEM concentration, and the quenching mode is static. The accuracy of the results was verified by the above methods. In addition, synchronous fluorescence and circular dichroism showed that CEM affected the conformation of TRF. Chapter 4: TRF, bovine serum albumin (TRF,) (BSA) was used to study the binding mechanism between TRF,BSA and CSI. The results show that the peak absorbance of BSA,TRF decreases with the addition of CSI, and the peak position corresponding to the highest absorbance is red-shifted by 3 nm,5 nm. It indicates that there is a new substance formation between CSI and BSA,TRF, and that the quenching of BSA,TRF absorption spectrum by CSI is static. The binding of TRF,BSA and CSI affects the 伪 -helix structure of TRF, resulting in its loosening and fluorescence quenching of TRF. Although the peak value of CD has changed, the shape and position of the peak have not been affected, which proves that the main structure in TRF,BSA is still 伪 -helix. Chapter 5: the mechanism of TRF- cefxitin sodium (CFS) system was studied with TRF as the research object. The results show that increasing the temperature of Ka decreases the stability of the products produced by the TRF,CFS reaction. The fluorescence quenching process is static, 螖 H 0, 螖 S 0, which indicates that TRF,CFS is bound by electrostatic force. The corresponding quenching level of 位 ex=280 nm is greater than that of 位 ex=295 nm, and Trp,Tyr and BSA,TRF are involved in the process of CFS and BSA,TRF. Many methods can be applied to the same study to make the results more accurate, so the new method can be expanded and explored on the basis of the research.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R96;O657.3

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